1. Field of the Invention
Safe, tasteless, odorless, non irritating, non aqueous spray compositions containing bioactive material administrable via the nasal cavity.
2. Discussion of the Prior Art
The use of nasal sprays to provide relief from the nasal stuffiness of colds and allergic rhinitis is widespread. Various sympathomimetic amines have been used to provide relief. Nasal decongestants stimulate the alpha-adrenergic receptors of the vascular smooth muscle. This constriction results in shrinkage of the engorged mucous membranes which promotes drainage; improves nasal ventilation and relieves the feeling of stuffiness.
Many decongestants are commercially available and are used to give various lengths of relief from 4 hours up to 12 hours. All of these decongestants are water soluble and are delivered in aqueous spray systems.
The decongestant solutions are delivered by spray from either a flexible plastic container that produces a mist when squeezed or by a hand operated mechanical pump.
These aqueous sprays are wet, cold and drip from the nose. They are very uncomfortable to use. Since they are aqueous based and the nozzle is inserted in the nostril, bacterial contamination of the product easily occurs. Nasal sprays are difficult to preserve.
The mucous layer lining the epithelium represents a barrier to drug absorption along with mucociliary clearance mechanisms of the nose leads to short residence time of aqueous systems at the site of absorption which limits the systemic availability of the drug.